I can't connect my old desktop to the internet directly through the router

[RaveRaze]

So I was going to turn my old desktop into a server and when I tried to connect it to the router I still had no internet access. I think this might be because it used to work with my Wireless adapter, the one I use on my computer now. If I revert to the original save state should a direct internet connection work?

On a partially related note, is it possible to install an operating system onto a computer without an operating system from a flash drive.

[g@mergeek]

What are you using to connect the desktop to the router?

[Demache]

Check your IP address settings.

[RaveRaze]

[QUOTE=G@merGeek;19748623]What are you using to connect the desktop to the router?[/QUOTE]

One of those Ethernet cords, I believe that's what they're called.

Also yes I do realize I'm an idiot